Bolster pin holder



June 22,1937. F. J. RODE BOLSTER PIN HOLDER Filed Jan. 7, 1935 thepress.

Patented June 22, 1937 UNITED STATES Are'r OFFICE 4 Claims.

My invention relates to a sheet metal drawing press and particularlyrelates to a holder for the bolster pins which are commonly mounted inthe bolster plate of a sheet metal drawing press.

As is well known to those skilled in the art, a bolster plate iscommonly mounted on the bed of a sheet metal drawing press and supportsa male forming die which cooperates with a female die mounted on areciprocating part or plunger of The female die acts inconjunction witha follower die slidably movable in coaxial relation to themale die andtends to grip the work. While the follower and female-dies hold thework, the female die draws it over the male forming die.

The follower die is commonly operated by I bolster pins which areinsertable and freely reciprocable in openings formed in the bolsterplate. The bolster pins are caused to reciprocate or are yieldingly heldagainst movement during the operations of the cooperating female die bya pressure pad on which they bear and by means of which they are heldupright in their respective openings. Oftimes during a retractory ornonworking stroke of the pressure pad, the bolster pins may dislodgethemselves from their particular openings in'the bolster plate and fallfrom an upright position on to the pressure pad or into the base of thepress, necessitating removal of the diesand bolster plate with itsattendant delay and expense in order to retrieve the pins and reinsertthe same in their respective openings.

My invention has for an object to provide 'means for holding the bolsterpins in their remeans for holding the bolster pins in their respectiveopenings, which functions independently of the bolster pin actuatingmeans or pressure pad.

A still further object of the invention is to .provide a bolster pinholding means which enables yieldingly resistant movement of the bolsterpins relative to the bolster plate thereby facilitating mounting ordismounting of the dies with reference to the bolster plate.

A more particular object is to provide an auxiliary pad supported by themain pressure pad and independently movable with respect thereto andforming means for yieldably supporting the bolster pins and diesoperated thereby in a normal upwardly extending position. A stillfurther common to all the pins and readily yieldable whereby themovement of one pin will cause a like movement of the others. -Thisfeature-is of particular advantage when setting up the press.

The invention consists in other features and advantages which willappear from the following description and upon examination of thedrawing. Structures containing the invention may partake of differentforms and still embody the invention. To illustrate a practicalapplication of the invention, I have selected a bolster pin holder as anexample of the variousstructures and details thereof that contain theinvention and shall describe the selected bolster pin holderhereinafter, it being understood that variationsmay be made withoutdeparting from p the spirit ofthe invention. The particular 'bolster pinholder selected is shown in the accompanying drawing and describedhereinafter.

Fig. 1 of the accompanying drawing illustrates a broken front sectionalview of a sheet metal press showing an embodiment of my invention in aninstalled position. Fig. '2 illustrates a 'view .of a section taken onthe plane of the line 2--2 indicated in Fig. 1. Fig. 3 illustrates anenlarged View of a section taken" along the plane of the line 3-3indicated in Fig. 2. a The sheet metal press shown in the drawing inpart, for'purposes of illustration, has aframe I comprising a crown 2, abase 3, and uprights'4. The uprights 4 support the crown 2 above thebase 3 and have suitable ways 5 in which is slidably supported areciprocable plunger 6. 'I'he plunger 8 is caused to reciprocate bymeans of any well-known mechanical means, such as the drive shaft 8,powered as from some suitable source of 3 power in a manner well knownto theart, The plunger 6 may carry a female .die member 9 shapedaccording to the work to be performed.

- The base 3 has a bed ID on which may be supported abolster plate I l.According to the 3 In operative relation to the with respect to the diemember M. The ring die [5 has a surface, such as that shownat I6, facingthe die member 9 which coacts with the die member 9 to grip the work andhold it while the die member 9 is being moved in mating relation to thedie 14. The ring die is caused to move and regulated in its movement bymeans of suitable bolster pins I1 freely and slidablysupported inopenings, I8 formed in the bolster plate.

The bolster pins "are caused to move and regulated in their movement bya pressure pad 20 located in the base 3 of the pressand reciprocated byany well-known means, such as the pneumatic bellows 2| which may besupplied from a suitable source of compression and be controlled bysuitable valve mechanisms to expand and contract in a manner well knownto those skilled in the art. It will be apparent that in a cycle ofoperation of the sheet metal press shown in Fig, 1, starting at theposition shown in Fig. 1, the plunger 6 will be moved upwardly away fromthe bed l and at the same time the follower or ring die l5 may be causedto move upwardly, if desired, stripping the die M of the work, until thesurface I6 of. the follower is flush with or slightly above, the head ofthe die member I4. A 7

piece of sheet metal is then placed on the surface l6 and the plunger 6caused to move toward the bed I0 and the die l5, the die member 9contacting the sheet metal. The follower die I5 is yieldingly heldagainst movement by the bellows 2| acting through the'pressure pad andbolster pins 11 so as to effect a firm clamping; of the sheet metalbetween the die 9 and follower [5. Upon continued movement of theplunger 6, the sheet metal is formed about the die M, as shown at 23,the follower die l5 retreating in timed relation to the advancement ofthe die 9 in a manner well known to the art. 7

It will be seen that as long as the pressure pad 20 is controlled in itsoperation and amplitude of stroke, the bolster pins II will bemaintained in their respective openings I8; However, as often happens,the source of pneumatic compression may fail causing the bellows tocollapse or the operator may over amplify'the retracting stroke of thepressure pad a distance sufficient to permit the upper ends of thebolster pins to escape their respective openings and fall from anupright position on to the pressure pad 20 or into the baseof the press.In order to replace the fallen pins, it is necessary to stop theparticular press, unmount the dies, and again reset the press.Considerable waste of time and expenditure of money is suffered by theuser in the replacement of the bolster pins.

In order to prevent the movement of the ends of the bolster pins I 1from their particular openings, Iprovidemeans independently movable withrespect to the pressure pad 20 and tending to- 'yieldingly hold the pinsupright in their respective opening. Preferably, such means comprises aplate or pin pad located in superimposed relation to'the pressure pad 20and supported in position by a plurality of pins 26. The pins 2t extendthrough openings 21 formed in the pressure pad 20 and are slidablyreciprocable with respect thereto. Each opening Z'Iis surrounded by adownwardly extending boss portion having an opening through which itsparticular associated pin 2,6 extends and may move. The lower .end ofeach pin 26 may be provided with a limiting stop pin 28. The boss iscored and forms a housing 32 and seat for a suitable compression 72,084,456 ,a ring die IS. The die I5 is steam movable spring 33 whichbears against chamber wall and the pin pad 25. The springs 33 arepreferably of a resiliency sufiicient to support the weight of the pinpad 25, the pins l1 and the particular follower die 15 in a fullyuppermost position. Thus, it will be apparent that the length of thepins 26 operating through the pad 25 supplement the length of thebolster pins l1 and in so far as maintaining the pins IT in theirrespective openings, provide the effect, during unloaded; periods of thepress, of a bolster pin substantially equal to the sum of the lengths ofa bolster pin l1 and that part of the pin 26 which extends below theboss portion 3!]. This enables increased stroke of operation of thepressure pad 20 and if desired,

foreshortening of bolster pins commonly in use.

In dismounting or mounting dies on the bolster plate, the bolster pinsmay be easily and manually moved against the yieldable springs 33 to aposition where the upper ends thereof are below the pper urface f t e hlst plate permitting the sliding of the dies over the bolster plate intoa desired position of installation or dismantling. Also hen h ad .5 imoved a inst the ield ing pressure of the springs, all the bolster pinsI! will follow requiring little further attention during setting ordismantling the dies. While in accordance with the provisions of thestatutes I have illustrated and described one of the best forms of myinvention nowknown to me,'those skilled in the art will readily appreciate and understand that many changes may be made in the form andconstruction disclosed herein without departing from the spirit of theinvention as set forth in the appended claims".

I claim: I 1. In a sheet metal press having a follower die, a bolsterpin for actuating said die, a pressure pad for actuating said pin, andmeans for moving said pressure pad, a bolster pin holder comprising a.pin pad supported in superimposed re-" lation to the pressure pad andfreely" movable with respect thereto, a plurality of springs disposedintermediate the pressure pad and the pin I pad, and a plurality of pinsconnected to the pin pad and extending through the pressure pad wherebythe pin pad may be guided in its movements relative to the pressure pad.

2. In a sheet metal press having a reciprocable pressure pad, a bolsterpin, a bolster pin holder comprising a movable pin pad for supportingthe bolster pin and located in superimposed relation to the pressurepad, a yieldable means extending between the pressure pad and pin padtending to maintain the pin pad in spaced rela tion to the pressure padvarying according to the movement of the pressure pad with reference tothe press whereby the bolster pin is maintained stationary withreference to the press during certain of the reciprocable movementsof-the pressure pad, and means engaging the pressure pad independent ofthe bolster pin for guiding the pin pad in its movements relative tosaid pressure pad whereby the pressure pad may engage thepin pad totransmit the force exerted bysaid pressure'pad during certain otherreciprocal movements thereof to, cause movement of the pin pad and thebolster pin with reference a tion and along the axis of said pin, abolster pin holder comprising means engageable by said pressure pad andadapted to engage the bolster pin in end abutting relation and readilydisengageable therefrom, a resilient means tending to yieldingly resistengagement between the said pressure pad and said pin holder means andmovement of the bolster pin toward the pressure pad with a pressure lessthan that exerted by means for reciprocating the pressure pad, and meansengaging the pressure pad independent of the bolster pin for guiding thepin holder means in its movement relative to said pressure pad wherebythe pressure pad may engage said pin holder means to transmit the forceexerted by said pressure pad during certain reciprocable movements ofsaid pressure pad to cause movement, with reference to the press, ofsaid pin holder means and the bolster pin.

4. In combination with a sheet metal press having a working die, abolster pin for actuating said die, a pressure pad for actuating saidpin and means for moving said pressure pad, a bolster pin holdercomprising a pin pad supported intermediate the pressure pad and thebolster pin and freely movable with respect to said pressure pad, acoiled spring disposed intermediate the pressure pad and the pin pad,and a pin disposed in concentric relation with respect to said springengaging the pin pad and pressure pad so as to guide the movements ofthe pin pad relative to the pressure pad.

FREDRICH J. RODE.

